1. Field of the Invention
The present invention relates to a system and method for supporting a logical sensor network (LSN), and more particularly to a system and method for supporting a LSN separate from a physical sensor network (PSN) to readily obtain sensing data required by a user or application program in an environment consisting of various types of PSNs.
2. Discussion of Related Art
With the development of sensor network technology, various types of sensor networks are being developed, and application fields of the technology are being diversified. Thus far, one application program has obtained required data using only one sensor network in most cases. However, as demands of application programs (e.g., an application program for metropolitan air atmosphere monitoring) that are more intelligent and manage a wide area increase, one application program frequently uses a plurality of sensor networks.
It is very difficult for a user or application program to directly use different types of multiple sensor networks because details of all the sensor networks should be recognized and programs for the respective sensor networks should be separately developed. To solve this difficulty, middleware that supports abstracting of sensor networks and query processing has been suggested. Due to the middleware, a user or application program can use different types of sensor networks without considering details of the respective sensor networks. Also, a user or application program can request sensing data from various sensor networks using a common query method (e.g., a structured query language (SQL)-based query).
However, even if middleware supporting abstracting of sensor networks is used, PSNs are connected to the middleware. Thus, a user or application program should have basic information (e.g., an operation mode, and a supported sensing type) on respective sensor networks to be used, and should specify all the sensor networks to be used for a query. Also, when a user or application program is indifferent to a sensor node in a specific area among sensor nodes connected to a PSN, the user or application program should specify an area condition for a query, or select only required data after receiving sensing data from all the sensor nodes.